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- 实验方案
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The Effect of In-Vivo Collagen Cross-Linking Procedure on the Material of Intracorneal Ring Segments
摘要： The material of Intracorneal Rings Segments (ICRS) has seemed to be polymerized after the absorption of Riboflavin and UV illumination in laboratory settings. This study aimed to assess the potential impact of in-vivo corneal crosslinking (CXL) on the chemical composition of ICRS. Within this contex, three ICRS samples (S1, S2 and S3) were extracted from patients' cornea, which formerly had undergone CXL treatment. Alterations on the chemical structure of PMMA rings were studied using Ultraviolet-Visible (UV-Vis) spectroscopy and Fourier Transform-Infrared (FT-IR) spectroscopy. An extracted ICRS from a patient who didn’t underwent CXL treatment, was also used as reference (S0). UV-Vis spectroscopy didn't identify any change in the specimens S1, S2 and S3. Nevertheless, FT-IR spectroscopic analysis showed alterations in the spectra of ICRS material of samples S1, S2 and S3, mainly at the 2800 to 3200 cm-1 spectral region [modification in band intensities of CH2 (2850 cm-1 and 2925 cm-1) and CH3 (2950cm-1)]. In conclusion, our results suggest crosslinking reaction in ICRS material after in-vivo CXL treatment. This should be taken into consideration prior to any CXL treatment of post ICRS implanted cornea.
关键词： FT-IR spectroscopy,Corneal crosslinking,INTACS,UV-Vis spectroscopy,Keratoconus
更新于2025-09-10 09:29:36
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Modulating chain conformations of polyvinyl alcohol through low cost and nontoxic glyoxal crosslinker: Application in high performance organic transistors
摘要： High leakage current and presence of numerous polar hydroxyl groups have often appeared as severe performance obstacles for polyvinyl alcohol (PVA) on its application in organic ?eld e?ect transistor devices. Herein, we report a facile, yet e?cient functionalization and chain structure modi?cation technique to enhance its e?cacy as a gate insulating layer. In this work, we have used glyoxal as a cross-linking agent of PVA to modulate its chain conformation and performed a detailed analysis to explore the role of glyoxal crosslinking on the electrical and structural properties of PVA. Applying various amount of glyoxal solution we have properly optimized the dose of the crosslinker to be used in the crosslinking reaction so that minimum amount of leakage can be achieved. Substantial improvement in the insulation properties as well as surface characteristics was observed after the structural modi?cation of the polymer. Correspondingly, organic FETs were fabricated using crosslinked PVA to gauge the e?ect of crosslinking on the device performance of the transistors. Post-crosslinking improvements in the polymer bulk and surface characteristics were clearly emulated in the device performance parameters. Field-e?ect mobility as high as 5.4 cm2/V-s and 1.7 cm2/V-s were achieved employing crosslinked PVA as gate dielectric layer in Dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene (DNTT) and pentacene based devices, respectively. Thus, our study illustrates the viability of crosslinking PVA using glyoxal and hence, can catalyze the limited use of PVA in electronic applications.
关键词： Crosslinking,Organic ?eld e?ect transistor,Gate dielectric,Polyvinyl alcohol,Glyoxal
更新于2025-09-10 09:29:36
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Light-triggered Covalent Assembly of Gold Nanoparticles for Cancer Cell Photothermal Therapy
摘要： Manipulating the assembly of gold nanoparticles (AuNPs) for maximizing the photothermal effect is a promising strategy for cancer therapy. Herein, taking advantage of the well-known tetrazole/alkene photo-click chemistry, we first demonstrated that small AuNPs (23 nm) decorated with both 2,5-diphenyltetrazole and methacrylic acid on the surface could form covalently cross-linked aggregates upon laser irradiation (λ = 405 nm). The in vitro studies indicated that the light-triggered assembling remarkably shifted the surface plasmon resonance of AuNPs to near-infrared (NIR) regions, which in consequence effectively enhanced the efficacy of photothermal therapy for 4T1 breast cancer cells. We thus believe that this new light-triggered assembly approach may offer a valuable tool for cancer treatment.
关键词： photothermal therapy,cancer cell,photo-crosslinking,gold nanoparticle,self-assembly
更新于2025-09-10 09:29:36
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Alginate-graphene oxide hydrogels with enhanced ionic tunability and chemomechanical stability for light-directed 3D printing
摘要： Nanocomposite hydrogels that incorporate 2D carbon nanomaterials could enable augmented and responsive behaviors not observed with polymeric matrices alone. In particular, non-covalent interactions could facilitate enhanced mechanical performance that can be self-recovered with external stimuli. Here, we demonstrate alginate-graphene oxide (GO) hydrogels using a non-covalent, ionic crosslinking mechanism compatible with light-directed 3D printing. We show that alginate-GO hydrogels exhibit improved mechanical performance in shear, compression, and tension, including a two-fold increase in shear modulus, a three-fold decrease in inelastic deformation, and a nine-fold increase in fracture energy relative to alginate-only hydrogels. Moreover, alginate-GO hydrogels are stabilized by hydrogen bonding between nanosheets and remain intact after removal of ionic crosslinkers by chelation. As a consequence, the shear modulus of these nanocomposite hydrogels can be tuned by over 500-fold via external ion concentration. We demonstrate that alginate-GO can be stereolithographically printed into robust, freestanding and overhanging 3D structures. These designer material architectures exhibit outstanding stability and superoleophobicity in high salt solution, which can be used to repel and manipulate a variety of oils. Overall, such nanocomposite hydrogels with engineered non-covalent interactions could enable “smart” multiresponsive and multifunctional devices for aqueous and marine environments.
关键词： Superoleophobicity,Ionic crosslinking,Chemomechanical stability,Graphene oxide,3D printing,Alginate,Nanocomposite hydrogels,Mechanical performance
更新于2025-09-10 09:29:36
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Phenol-functionalized polymerization control additives for negative tone epoxide crosslinking molecular resists
摘要： Controlling undesired polymerization in nominally unexposed regions is critical to achieving high-resolution, defect-free patterns when using negative tone molecular resists based on the crosslinking of epoxides. Two onium salt additives, a photodecomposable nucleophile (PDN) and a photoacid generator (PAG), were functionalized with phenols in order to investigate their use as generalized additives capable of slowing crosslinking and improving the resolution of a variety of epoxide resists. Presented here is a phenol-functionalized PDN [tris(4-hydroxyphenyl)sulfonium tri?ate (TPS-OH-Tf )] and a phenol-functionalized PAG [tris(4-hydroxyphenyl)sulfonium antimonate (TPS-OH-SbF6)] used in combination with a model epoxide resist (4-Ep). Utilizing additives that contained phenols resulted in a decrease in resist sensitivity, but enabled higher additive loadings which could be used to offset this loss in sensitivity. Using TPS-OH-SbF6 did not provide enough polymerization control to prevent line broadening, and the use of TPS-OH-Tf was still required to achieve sub 35 nm 1:1 line:space patterns. Adding TPS-OH-Tf was also found to improve pattern collapse behavior at reduced (<25 nm) feature sizes. Initial patterning using 100 keV electron-beam lithography showed that the resolution of 4-Ep was improved to 15 nm 1:1 line:space patterns using these phenol-functionalized additives and demonstrate the potential of these additives to improve the resolution of a variety of epoxide crosslinking molecular resists.
关键词： phenol-functionalized additives,polymerization control,molecular resists,negative tone epoxide crosslinking,high-resolution patterning
更新于2025-09-09 09:28:46
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Electrical Conductivity Modulation of Crosslinked Composite Nanofibers Based on PEO and PEDOT:PSS
摘要： The aim of this work is to investigate the development of nano?ber mats, based on intrinsically conductive polymers (ICPs), which show simultaneously a high electrical conductivity and mandatory insoluble water properties. In particular, the nano?bers, thanks to their properties such as high surface area, porosity, and their ability to o?er a preferential pathway for electron ?ow, play a crucial role to improve the essential characteristics ensured by ICPs. The nano?ber mats are obtained by electrospinning process, starting from a polymeric solution made of polyethylene oxide (PEO) and poly(styrene sulfonate) (PEDOT:PSS). PEO is selected not only as a dopant to increase the electrical/ionic conductivity, as deeply reported in the literature, but also to ensure the proper stability of the polymeric jet, to collect a dried nano?ber mat. Moreover, in the present work, two di?erent treatments are proposed in order to induce crosslinking between PEO chains and PEDOT:PSS, made insoluble into water which is the ?nal sample. The ?rst process is based on a heating treatment, conducted at 130°C under nitrogen atmosphere for 6 h, named the annealing treatment. The second treatment is provided by UV irradiation that is e?ective to induce a ?nal crosslinking, when a photoinitiator, such as benzophenone, is added. Furthermore, we demonstrate that both crosslinking treatments can be used to verify the preservation of nanostructures and their good electrical conductivity after water treatment (i.e., water resistance). In particular, we con?rm that the crosslinking method with UV irradiation results to being more e?ective than the standard annealing treatment. Indeed, we demonstrate that the processing time, required to obtain the ?nal crosslinked nano?ber mats with a high electrical conductance, results to being smaller than the one needed during the heating treatment.
关键词： PEO,PEDOT:PSS,intrinsically conductive polymers,electrical conductivity,nano?ber mats,water resistance,electrospinning,crosslinking
更新于2025-09-09 09:28:46
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A Versatile Dynamic Light Scattering Strategy for the Sensitive Detection of Plant MicroRNAs Based‐on Click Chemistry‐Amplified Aggregation of Gold Nanoparticles
摘要： Plant microRNAs (miRNAs) are naturally 2′-O-methylated at the 3′-terminal, so they cannot be efficiently detected by traditional target-triggered polymerization reactions. Herein, a simple but robust enzyme-free sensing strategy is developed for plant miRNA analysis by using dynamic light scattering (DLS) technique to monitor the click chemical ligation-amplified crosslinking of gold nanoparticles (AuNPs). Combining the enzyme-free cycling chemical ligation-mediated signal amplification, and the intrinsic outstanding ability of DLS for discriminating the extremely low level of particle aggregation in a large pool of monodisperse AuNPs, high sensitivity is achieved and as low as 78.6 fM plant miRNA can be easily detected.
关键词： crosslinking,click chemistry,plant microRNA,dynamic light scattering (DLS),gold nanoparticles
更新于2025-09-09 09:28:46
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Impact of corneal cross-linking combined with photorefractive keratectomy on blurring strength
摘要： The aim of this study was to evaluate the impact of corneal cross-linking combined with photorefractive keratectomy (PRK) on blurring strength. A total of 63 patients with keratoconus were recruited for this study, and two study groups were formed according to the therapeutic intervention: corneal collagen cross-linking (CxL) group (33 patients) received corneal cross-linking according to the Dresden protocol, while the rest additionally received topography-guided photorefractive keratectomy (tCxL). The impact of surgical procedure on blurring strength was assessed by power vector analysis. Potential association between blurring strength and vision-specific quality of life was assessed using the National Eye Institute Visual Function Questionnaire (NEI-VFQ) 25 instrument. Blurring strength presented excellent correlation with NEI-VFQ scores both preoperatively and postoperatively (all P,0.01). Both groups demonstrated nonsignificant changes in best-corrected visual acuity; however, only the tCxL group had significant reduction in blurring strength (13.48+10.86 [preoperative], 4.26+7.99 [postoperative], P=0.042). Only the combined treatment (tCxL) resulted in significant reduction in blurring strength. Moreover, the excellent correlation of blurring strength with NEI-VFQ scores indicates its reliability as an index of self-reported quality of life in keratoconus, since it seems to address the nonsignificant changes in best-corrected visual acuity following CxL treatments that are conceived as subjective improvement by the patient.
关键词： blurring strength,keratoconus,tCxL,cornea crosslinking
更新于2025-09-04 15:30:14
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Thermally resistant photocrosslinked damping poly(phenylene oxide)-fluorosilicone rubber films with broad and high effective damping temperatures
摘要： The development of an energy-ef?cient strategy to prepare thermally resistant damping materials with high damping capacities (tan δ values) and broad effective damping temperature ranges (ΔTs) at high temperatures (>150 (cid:1)C) is still an interesting challenge. In this study, a graft copolymer (PSi-g-APPO) was synthesized through the reaction between hydrogen-terminated ?uorosilicone and allyl poly(phenylene oxide) (APPO), and a unique kind of photocrosslinkable ?lm (coded as GFA) consisting of FSR, APPO and PSi-g-APPO was prepared. The resultant GFA has high thermal resistance, wide ΔT, and high tan δ. When the weight ratio of APPO to FSR to PSi-g-APPO was 81:9:10, the obtained ?lm exhibited a broad ΔT of 64 (cid:1)C and a high tan δ (≤1.01) from 157 to 221 (cid:1)C; this was the best comprehensive performance among the GFA systems. The mechanism behind the excellent integrated performance of GFA was studied and was proven to be due to the unique structure of the heterogeneous GFA system.
关键词： thermal properties,crosslinking,structure–property relationships,blends,?lms
更新于2025-09-04 15:30:14
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Effect of crosslinking stage on photocrosslinking of benzophenone functionalized poly(2-ethyl-2-oxazoline) nanofibers obtained by aqueous electrospinning
摘要： In this study, benzophenone was introduced onto partially hydrolyzed poly(2-ethyl-2-oxazoline) (PEtOx-PEI) to prepare a poly(2-ethyl-2-oxazoline)-benzophenone (PEtOx-BP) copolymer, which was used to produce water stable nanofibers via aqueous electrospinning and photocrosslinking. Three different ultraviolet (UV) irradiation methods, i.e. pre-crosslinking before electrospinning, in-situ crosslinking during electrospinning and post-crosslinking after electrospinning, were used to prepare crosslinked nanofibers. The influence of UV-irradiation at these different stages of the nanofiber production process was investigated in terms of alterations in viscosity, nanofiber morphology and water stability of the fibers. It was shown that pre-crosslinking the polymer solutions had a great influence on the solution viscosity which could both positively or negatively alter the stability of the electrospinning process. Whereas the strategy of crosslinking nanofibers during the production process did not lead to uniform nor water-stable nanofibers, the pre-crosslinking and post-crosslinking strategies greatly increased the water stability of the nanofibers. In both techniques the crosslinking density and therefore water solubility can be easily tuned by manipulating the polymer concentration, UV-irradiation time and membrane thickness. Complete insolubility, i.e. the formation of crosslinked networks, was achieved by the post-crosslinking strategy. This work provides straightforward methods to increase the water stability of the PEtOx nanofibers, which will definitely be of great value to biomedical applications such as drug delivery and tissue engineering.
关键词： nanofibers,benzophenone,crosslinking,UV-irradiation,electrospinning,poly(2-ethyl-2-oxazoline)
更新于2025-09-04 15:30:14